How to use the ytcc.database.Channel.displayname function in ytcc

def init_order(self) -> Iterable[Any]:
        col_mapping: Dict[str, Column] = {
            "id": Video.id,
            "date": Video.publish_date,
            "channel": Channel.displayname,
            "title": Video.title,
            "url": Video.yt_videoid,
            "watched": Video.watched
        }
        for key in self._config["YTCC"]["orderBy"].split(","):
            sort_spec = list(map(lambda s: s.strip().lower(), key.split(":")))
            col = sort_spec[0]
            desc = ""

            if len(sort_spec) == 2:
                desc = sort_spec[1]

            column = unpack_or_raise(col_mapping.get(col),
                                     BadConfigException(f"Cannot order by {key.strip()}"))
            column = column.collate("NOCASE")
            yield column.desc() if desc == "desc" else column

def get_channels(self) -> List[Channel]:
        return self.session.query(Channel).order_by(Channel.displayname).all()

def rename_channel(self, oldname: str, newname: str) -> None:
        """Rename the given channel.

        :param oldname: The name of the channel.
        :param newname: The new name of the channel.
        :raises ChannelDoesNotExistException: If the given channel does not exist.
        :raises DuplicateChannelException: If new name already exists.
        """
        query = self.session.query(Channel).filter(Channel.displayname == newname)
        if query.one_or_none() is not None:
            raise DuplicateChannelException()

        try:
            channel = self.session.query(Channel).filter(Channel.displayname == oldname).one()
            channel.displayname = newname
        except NoResultFound:
            raise ChannelDoesNotExistException()